Radio receiving system



Nov. 17,1925. 1,562,056

C. W. RICE RADIO RECEIVING SYSTEM Filed April 21, 1921 2 Sheets-Sheet l i i J i I PHASE 1 g P0 4 TOI? I l PHAJE PHASE rrom TO? l-POI'A TOF?\ X I 1 l .5" I 4 PHASE 057507 01? ROTATOR 12 3/ J0 s x In ve ntor His fittorne u Nov. 17, 1925. 1,562,056

C. W. RICE RADIO RECEIVING SYSTEM Filed April 21, 1921 2 Sheets-Sheet 2 Fig.2.

UETECT OE 3- 2 E DETEC' To C; 1 7575 70??? F 7 :E a I I. E i I PHAS I- 5 07.4 r01? 9 l Vantor. Chest 1' W. Rica, by I, fiZl LVQ His Attorney.

atent Nov. 17, I925.

u ruo STATS PATENT OFFICE.

CHESTER W. RICE, OF SCHENECTADY, NEW YORK, ASSIGNOE TO GENERAL ELECTRIC," COMPANY, A CORPORATION OF NEW YORK.

RADIO. .REGEIVING SYSTEM.

Application filed Api'il 21, 1921. Serial No. 463,102.

To all whom it may concern:

Be it known that I, CHESTER W. Rica, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Radio Receiving Systems, of which the following is a specification.

My present invention relates to radio receiving systems, and more particularly to systems of the class in which a plurality of widely separated receiving antennae are connected by transmission lines to a central receiving station.

One of the objects of my invention is to provide an improved method of operating such a system whereby an efiicient reception of desired signals may be secured and the effects of disturbing influences either from nearby stations or from static may be minimized. Another object of my invention is to provide an improved system of the class described whereby a more eflicient reception of desired signals may be obtained. y

In order to attain the objects of my in vention I rovide a plurality of receiving antennae W ich are located at widely separated points, so chosen geographically that the intensity. or phase relatlon between the signaling impulses'and disturbing influences will be different at the different points of reception. I also 'tively impressing t e currents received upon the receiving apparatus so that it will be possible to select for the desired reception the currents having the most favorable ratio between signal and disturbing influence. In addition I provide means for varying the phase and intensity of the currents impressed upon the receiving apparatus so that by suitable adjustment the designed signaling currents received upon different antennae may be brought into phase or approximate phase with one another and caused to add am litudes in the receiving apparatus while t e disturbing influences will at the same time be more or less out of phase and will combine in heterogenous phase relation and'therefore increase less rapidly than the desired signals with an increasing number of receiving antennae. Asa result what is commonly known as the stray ratio; that is, the ratio between the rovide means for selecstrength of the signaling currents and stray currents, will be greatly improved.

When the receiving antennae are widely separated long transmission lines must be employed for transmitting the received signaling currents to the receiving station.

This involves difliculties in line construction to reduce the line losses to a minimum. To overcome this disadvantage I may provide detectors at each of the receiving antennae and transmit the detected currents over the transmission lines to the central receiving station. As a result the line construction may be greatly simplified and the line losses greatly reduced. In case continuous wave signals are to be received it isdesirable that of the detectors and utilizethe transmission lines for transmitting this current to the lndividual detectors. This source may be of a frequency near thatof the signals to be received so that audible frequency beats may be. readily produced by the detectors.

In this case efliciency of transmission for the high frequency current is not so important as the source of control current may easily be made to furnishthe small amount of'energy required for the operation of the detectors even though thetransmission losses are comparatively large.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims,

the accompanying drawing in which Fig. 1 showsdiagrammatically a simple form 'of receiving system whereby my invention may;- be carried into effect when the transmission lines are employed for conveying the radio frequency signaling currents to the receiving station; Fig. 2 illustrates a l'IlOdlfiCtltiOD of in invention in which detectors are provided for each receiving antenna and the control current is sent out over the transmission lines from the receiving station to each of these detectors for producin currents of lower frequency for transmission to the receiving station; and Fig. 3 illustrates a modification in the manner of transmitting the control currents from the receiving station to the individual detectors.

As indicated in Fig. 1, my receiving system comprises a plurality of widely separated receiving antennae 1, 2, 3, 4, 5, connected by individual transmission lines 6, 7 8, 9, 10, to a receiving station. These antennm may be of any particular type desired and their locations may be so chosen and so widely separated that the intensity and phase relations between the desired signaling currents and disturbing influences either of static or interfering stations will normally be different at the different antennze.

While I have indicated all of the receiv ing antennae as being located at a distance from the receiving station, it is obvious that if desired one of them may be located at the receiving station. The currents received upon the individual antennae may be 1m- 1 pressed by means of the usual coupling transformers upon the transmission lines and at the receiving station the signaling currents transmitted over the transmisslon lines may be impressed by means of intensity couplers upon phase rotators 11, 12, 13,

14, 15, all of which may be connected to the receiving apparatus. The receiving apparatus which may be of any type desired, 15 indicated merely by the rectangle 16. Any convenient means such, for example, as switches 17 18, 19, 20, 21, may be employed for selectively impressing upon the receiving apparatus the currents received upon any one or more of the antennae. By varying the adjustment of the phase rotators and intensity couplers the desired slgnahng currents received upon any two or more of the antennae may be brought into phase or approximate phase with one another so as to add amplitudes in the receiving apparatus While the currents due to disturbing influences will at the same time be more or less out of phase and will combine in heterogeneous phase relation. Theapparatus 1ndicated may be utilized for receiving 1n a large variety of ways. It may be found that currents received upon one of the antennae have a much more favorable stray ratio than the currents received upon any of the other antennae, in which case the current having the most favorable stray ratio may be selected for the desired reception, and this current alone impressed upon the receiving appa- 1 ratus.

. be obtained which gives a more favorable stray ratio than any antenna alone and this particular combination may then be utilized for the desired reception. By means of the apparatus indicated, the individual antenna necaosc or combination of antennae employed for reception may be varied at Wlll to meet varying disturbing conditions, such, for exam- .ple, as disturbances produced by thunderstorms travelling across the country in such a way that at one time one of the receiving antennae is most seriously affected while 'a little later one of the other antennae is affected to a greater extent.

In the arrangement thus far described it is assumed that the signaling currents of radio frequency are transmitted over the transmission lines to the receiving station. Since these transmission lines will preferably be of considerable length special precautions may be required in the construction of the transmission lines to minimize and balance the transmission losses, and in any case, there will be unavoidable losses in transmission which may prevent satisfactory reception. To overcome such disadvantages I have shown in Fig. 2 individual detectors 22, 23, 24, 25, 26, associated with the different antennae for detecting the received currents and producing ateach receiving point a current of a lower, preferably, audible frequency for transmission over the transmission lines to the receiving station. It is of course desirable that the lower frequency currents thus produced for transrmssion should all have the same frequency, and to insure that they shall have the same frequency I provide a source of control current 27 at the receiving station. Current supplied by this source is transmitted over the individual transmission lines to the detectors to control their operation. This control current may be of a frequency only slightly different from that of the signaling currents. The control current may beimpressed upon the transmission lines through the condensers 28 at the receiving station and from the transmission line to the detectors through condensers 29 at the separate receiving points. These condensers should be of such value as to offer a high impedance to low frequency signaling currents transmitted whereby the efficiency of transmission of the low frequency currents will be unimpaired. Choke coils 30 at the central receiving station, and 31 at the individual receiving points, may be provided to keep the higher frequency control currents from circulating in portions of the circuit. where they arenot desired. The individual phase rotators, intensity couplers, and selective switches are provided at the receiving station in this'case, and may be operated in the same manner as the corresponding elements in the system shown in Flg. 1. In

this case the transmission lines need only be designed for efficient transmission of the low fre uency currents as the source 27 may readily e made large enough to supply all of the power required for the operation of the detectors altho the line losses may be comparatively large.

' In Fi 3, I have shown diagrammatically a modifi cation of the manner in which the control current is transmitted over the transmission lines. In this case the two con-- duetors of the transmission line connected in parallel are used for one side of the control current circuit and a ground return is used for the other side.

While I have indicated and described the preferred embodiments of my invention, it will be apparent that my invention is by no means limited to the particular embodiments shown and described, but that many modifications in the arrangement, connections, and method of operating the apparatus, may be made without departing from the scope of my invention as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is

1-. The method of operating a radio receiving system comprising a piurality of widely separated receiving antennae and local detectors connected by transmission lines to a central receiving station which consists in transmitting over the transmission lines from the central receiving station to each local detector radio frequency currents, producing by means of the currents thus transmitted audio frequency currents, transmitting the audio frequency currents thus produced to the receiving station, selectively impressing upon the receiving apparatus the audio frequency. currents thus transmitted, and selecting for .the desired reception of signals the currents having the most favorable stray ratio. r

2. The method of o erating a radio receiving system comprising a plurality of widely separated receiving antennae and local detectors connectedby transmission lines to a central receiving station which consists in transmitting over the transmission lines from the central receiving station to each local detector radio frequency currents, producing by means of the currents thus transmitted audio frequency currents, transmitting the audio frequency currents thus produced to the recelving station, selectively impressing upon the receiving apparatus the audio frequencv currents thus transmitted, adjusting the phase and intensity of the currents impressed upon the receiving apparatus from the different detectors so that the currents produced by desired signals will add amplitudes in the receiving apparatus, and currents produced by disturbmg influ ences will combine in heterogeneous phase relation, and selecting for the desired reception of signals the resulting combination of currents having the most favorable stray ratio. Y

3. The method of operating a. radio re ceiving system comprising a plurality of widely separated receiving intennae and local detectors connected by transmission lines to a central recei 'ing station which consists in transmitting ever the transmission lines from the central receiving station to each local detector a current for controlling the operation of the detector, producing by means of the currents thus transmitted audio frequency currents at each detector, transmitting the audio frequency currents thus produced to the receiving station, selectively impressing upon the receiving apparatus the audio frequency currents thus transmitted, and selecting for the desired reception of signals the currents having the most favorable stray ratio.

4. The method of operating a radio receiving system comprising a plurality of widely separated receiving antennae and local detectors connected by transmission lines to a central'receiving station which consists in transmitting over the transmission lines from the central receiving station to each local detector a current for controlling the operation of the detector, producing by means of the currents thus transmitted audio frequency currents, transmitting the audio frequency currents thus produced to the receiving station, selectively impressing upon the receiving apparatus the audio frequency currents thus transmitted, adjusting the phase of the currents impressed upon the receiving apparatus from the different detectors so that the currents produced by desired signals will add amplitudes in the receiving apparatus, and currents produced by disturbing influences will combine in heterogeneous phase relation, and selecting for the desired reception of signals the resulting combination of currents having the most favorable stray ratio.

5. The combination in a radio receiving station of a plurality of widely separated a detector associated with each of said antennae, a source of control current at the receiving station for controlling all of the detectors, means for impressing the control current upon the transmission lines, meansfor impressin the controlcurrentflowing in the transmission lines upon the detectors to produce currents thereinof a fre uency lower than that of the signals to received, means for impressing the currents of lower frequency thus produced upon the transmission lines means for selectively impressin the currents of lower frequency transmitted upon the receiving apparatus, and means for adjustin the phase and intensity of the currents t us impressed upon the receiy'ing apparatus. i

6. The combination in a radio receiving station of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antennae with the receiving station, a detector associated with each of said antennae, a source of control current at'the receiving station for controlling all of the detectors, means for impressing the control current upon the transmission lines. means for impressing the control current flowing in the transmission, lines upon-the detectors to produce currents therein of a frequency lower than that of the signals to be received, and means for impressing the currents of lower frequency thus produced upon the transmission lines.

7. The {combination in a radio receiving station of a plurality of widely separated receiving antennze, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antennae with the receiving station, a detector associated with each of said antennae, a source of high frequency control current at the receiving station for controlling all of the detectors, means for impressing the control current upon the transmission lines, means for impressing the control current flowing in the transmission lines upon the detectors to produce currents therein of a frequency lower than that of the signals to be received, and means for impressing the currents of lower, frequency thus produced upon the transmission lines.

8. The combination in a radio receiving station of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, trans- -mission lines connecting each of said receiving antennae with the receiving station, a detector associated with each of said antennae, a source of control current at the receiving station of slightly different frequency from that of the signals to be received for controlling all of the detectors, means for impressing the control current upon the transmission lines, means for impressing the control current flowing in the transmission lines upon the detectors to produce currents therein of a frequency lower than that of the signals to be received, and means for impressing the currents of lower frequency thus produced upon the transmission lines.

9. The combination in a radio receiving station, of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antennae with the receiving station, a; detector associated with each of said antennae for producing by means of si aling currents to be received currents 0 lower frequency, means for impressing the currents of lower frequency thus produced upon the transmission lines, means for selectively impressing the currents of lower frequency transmitted upon the receiving apparatus. and means for adjusting the phase and intensity of the currents thus impressed upon thereceiving apparatus.

[0. The combination in a radio receivin system of a plurality of widely separated receiving antennae, receiving apparatus lo- *ated at a central receiving station, transmission lines connecting each of said receiving antcnnzc with the receiving station, a detector associated with each of said antennae, a source of control current at the receivingstation of slightly different frequency from that of the signals to be received for controlling all of the detectors, means for impressing the control current upon the transmission lines, means for impressing the control current flowing in the transmission lines upon the detectors to produce audio frequency currents therein and means for impressing the audio frequency currents thus produced upon the transmission lines.

11. The combination in a radio receiving system of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antenna: with the receiving station, a detector associated with each of said antennae, a source of control current at the receiving station of slightly different frequency from that of the si als to be received for controlling all 0 the detectors, means for impressing the control current upon the transmission lines, means for impressing the control current flowing in the transmission lines upon the detectors to produce audio f requency currents therein, means for impressing the audio frequency currents thus produced upon the transmission lines, means for selectively impressin the audio frequency currents transmitted upon the receiving apparatus, and means for adjusting the phase and intensity of the currents thus impressed upon the receiving apparatus.

12. The combination in a radio receiving station of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving'antennae with the receiving station, a detector associated with each of said antennae, a source of control current at the receiving station for controlling all of the detectors, means for transmitting the control current to all of the detectors to produce currents therein of a frequency lower than that of the signals to be received, and

means for impressing the currents of lower,

frequency thus produced upon the transmission lines.

13. The combination in a radio receivin station of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antennae with the receiving station, a detector associated with each of said antennae, a source of control current at the receiving station of slightly difi'erent frequency from that of the signals to be received for controlling all of the detectors, means for transmitting the control current to all of the detectors to produce audio frequency currents therein and means for impressing the audio frequency currents thus produced upon the transmission lines.

14. The method of operating a radio receiving system comprising a plurality of widely separated receiving antennae connected by transmission lines to a central receiving station which consists in producing at each antenna by means of signaling cur rents received thereon currents of lower frequency, transmitting the currents of lower frequencies over the transmission lines to the receiving station, selectively impressing upon the receiving apparatus the lower frequency currents thus transmitted, adjusting the phase and intensity of the currents impressed upon the receiving a paratus from the different transmission ines so that the currents produced by desired signals will add amplitudes in the receiving apparatus and currents produced by disturbing influences will combine in heterogeneous phase relation and selecting for the desired reception of signals the resulting combination of currents having the most favorable stray ratio.

In witness whereof, I have hereunto set my hand this th day of April, 1921.

CHESTER W. RICE. 

